REPORT OF THE MICROSCOPIST. 



Sm -^ I have the honor to submit herewith my fourteenth annual re- 

 port. The work of this division for the past year has heeu chiefly cou- 

 tined to the detection of adulterations of food, with special reference to 

 butter, oleomargarine, butteriue, and the fats used in the manufacture 

 of oleomargarine cheese, having in view the discovery of a method by 

 which the respective fats employed in the manufacture of butter substi- 

 tutes may be detected Avith the microscope, thus assisting to render 

 operative the law relating to this subject. 



Chemical methods of testing butter and fats are found to be neces- 

 sarily slow and not always satisfactory, as is affirmed by the leading 

 chemists of Europe and America. Prof. A. Voelcker, chemist of the 

 Eoyal Agricultural Society of England, recently acknowledged before 

 a parliamentary committee that the reasons why the butter laws of 

 England were wholly inoperative was because there was no chemical 

 method known to him whereby oleomargarine could be distinguished 

 from butter. 



In considering tlie fact that every known fat, vegetable and animal, 

 presents to the "touch and sight different physical properties, I became 

 convinced, fats being composite bodies, that the proportions of their 

 fatty combinations might vary and give rise to different forms of crys- 

 talline structure. Experiments have thus far demonstrated the correct- 

 ness of my theory. 



Agreeably with your instructions I was present at the annual meet- 

 ing of the American Society of Microscopists, held at Cleveland, Ohio, 

 in August last, and read a paper on the crystals of butter and other 

 animal and veget;vble fats, with illustrations on the blackboard. 



In consequence of the novelty and apparent value of the facts stated, 

 contained in discoveries wliich are the result of years of patient investi- 

 gation, the president of the society, Prof. H. L. Smith, of Hobart Col- 

 lege, Geneva, X. Y., with ray sanction, appointed a committee of five 

 men, experienced in microscopy, to investigate and report upon the 

 merits of the discoveries. On the following day the chairman of said 

 committee stated luiblicly, at the morning meeting, that I had verified 

 every statement made. The full report of this committee will be pub- 

 lished in the society's annual report. 



I also read a paper bctbre the cheiiiical section of the American As- 

 sociation for the Advancement of Science, held at Ann Arbor, Mich., 

 in the month of September, an abstract of which is now published by 

 the ^society. 



By invitation of the president of the American Textile Society and 



agreeably with your instructions, I prepared and read, at the annual 



meeting in October, a paper relating to the structure of textile fibers 



and the changes effected thereon by the action of chemical reagents. 



This paper is included, as the experiments were originally a part of my 



unpublished division work. 



(89) 



